Door lock switch



A ril 12, 1938. r c. M. BIDEFELDT 2,113,672

' DOOR LOCK SWITCH Filed Dec. 4, 1955 3 Sheets-Sheet 1 April 12, 1938- c. M. BIDEFELDT DOOR LOCK SWITCH Filed Dec. 4, 1935 3 Sheets-Sheet 2 April 12, 1938 c. M. BIDEFELDT DOOR LOCK SWITCH Filed Dec. 4, 1935 3 Sheets-Sheet 5 Patented Apr. 12, 1938 UNITED STATES PATENT QEFIQE Application December 4, 1935, Serial No. 52,849

In Sweden July 18, 1934 1 Claim.

This invention relates to a door lock of the kind having a lock bolt which can be operated by the door handle after it has been partly retracted by means of a key, and wherein means are provided for operating an alarm signal in case an attempt should be made to open the look by means of a false key or to force the lock bolt into the lock.

The invention consists in the first place in the provision of a catch adapted to retain the look bolt in retracted position; and key-operated means for releasing it.

The lock is also provided with a tumbler or tumblers adapted to yield pivotally to pressure on the lock bolt from the outside, and of means for operating the alarm under the influence oi such yielding movement.

The invention is illustrated by way of example in the accompanying drawings.

Fig. 1 represents a side view showing the interior of the lock,

Figs. 2 and 3 are views showing parts of the mechanism in difi'erent positions,

Fig. 4 is a section on the line IV-IV of Fig. 1,

Fig. 5 is a view like Fig. 1 with several parts of the mechanism removed,

Figs. 6 and 7 are sections on the line VI-VI and VII-VII respectively of Fig. 5, and

Fig. 8 is a diagram of the signalling circuit.

The lock mechanism is enclosed in a casing having side walls I and 2, a front wall 3, and a rear wall 4. A latch bolt 5 is guided in known manner in an aperture in the front wall 3 and controlled by a spring 6. The latch spindle 8 is supported in a bearing 9 and carries an arm I by means of which the door handle (not shown) is connected to the latch bolt. The lock bolt in is controlled by a spring I I and guided by a heel I2 connected to the wall I. It can be shot and 40 retracted either by means of an outer key I 4 inserted through a key-hole I3, or by means of an inner key I 6 inserted through a key-hole I5.

The lock bolt I ll has a tail piece I9 which is provided with an opening 29 forming two abutments I1 and I8 for engagement with the key I4. An abutment 2l-is provided at the lower edge of the tail piece for cooperation with the key I6. On the upper edge of the lock bolt Ill there is a fiat projection 22 which is secured to the bolt by means of a flange portion 23. The inwardly directed edge of this projection has a recess 24 in which the tumblers 25 of the lock engage with their arms 26. Another projection 27 on the lock bolt co-operates, for a purpose later to be described, with one arm 28 of a doublearmed lever which turns about a pivot 30 and is controlled by a spring 29. The other arm 30 of the lever bears, under the influence of the spring as, against a projection 3i on the latch spindle 8. In the top side of the tailpiece I9 there is a notch 32 into which a catch 34 is adapted to snap in a given position of the lock bolt as will be later described. The catch turns about a pivot 34 and is controlled by a spring 33. In the bottom side of the tail piece there is a notch 35 into which a catch 3! is adapted to snap with either of its two teeth 38 and 39 in a manner which will also be described later. This catch moves about a pivot 3i and is controlled by a spring 35. The lower end of the catch 31 is fitted with two arms 38' and 39 which cooperate with the supporting pin ll of the spring I I for limiting the movement of the catch.

A bell crank 40, 4i is pivotally mounted on a pin 42 and controlled by spring 43. One arm 56 co-operates in a manner later to be described, with the projection 22 of the lock bolt Ill. The other arm bears, under the influence of the springs 43, against the free end of a cup-shaped lever 44 which turns about a pivot 15 and is controlled by a spring 46. The lever 45:! carries a ball 41 and is capable of placing said ball in a position where it partly projects through an opening 48 in the wall 3 of the lock casing.

The tumblers 25 are mounted on a common pivot pin 49 and are controlled by springs 50 which tend to hold them in contact with a supporting pin 55, i. e., in the position shown by solid lines in Fig. 5. In addition to the arm 23 each tumbler has two arms E32 and 53 which are parallel to the arm 2t and adapted to eo-operate in known manner with the keys and I6. In one of the tumblers the arm 28 is replaced by a blade spring 26 which is somewhat longer than the arm 26 and which serves a purpose later to be described.

Mounted on a pivot fi l in the upper portion of the lock casing is a double-armed, flat lever 55, 56 which tends, under the influence of a spring or merely by friction, to remain in any position into which it is moved. The lower arm 55 of the lever is located in the path of the upper ends of the tumblers 25, and the other arm can be made to bear against a contact 51 to which the lead of an electric signalling device is connected. The part 58 of the lead situated within the lock casing, is carried by an insulator 59 of suitable type.

The signalling device comprises an electric bell 60 one terminal of which is connected to a battery (ii. The other terminal is connected to a lead 2 with a bar 63 Which is secured to the door frame and which makes contact with the lock bolt ill in the closed position of the door. The battery 51 is further connected. through a lead 64 with a blade spring 65 which is connected to the door frame and which is adapted to make contact with a blade spring 66 on the door when the latter is closed. The spring 66 is connected by a lead 6'! to the lead portion 58 located within the lock casing. Thus, when the door is closed, the signalling circuit extends through the parts it, 22, iii, 25, 55, 56 and will be closed by contact between the parts 56 and 51 in case of an attempt to open the lock forcibly or by means of a false key. A rod 68 shown in Fig. 1, can be inserted into the lock through an opening 69 in the wall 3 for restoring the lever 55, 56 to its normal position (Fig. 1) if the lever should for one reason or another have been shifted from this position.

Fig. 1 shows the door closed. Both bolts are completely shot, and the ball 41 is held by the door frame in depressed position within the look. If the door is to be opened from the outside, the key M is given one part'turn and the key, by cooperation with the abutment l8, moves the lock bolt into the position shown in Fig. 2 where it is retained by the catch 34 which for this purpose engages in the notch 32. On the door handle being thereupon depressed, the arm 1 causes the parts 3i, 30, 28, and 21 as well as the two bolts to be retracted until the bolts are flush with the wall 3. The catch 34 moves into the position shown in Fig. 3 and disengages the bolt Ill. If now the door is opened, the lever 44 moves the ball 4? into the outer position shown in Fig. 3, and the arm 46 is moved by the spring 43 into engagement with the opposite edge of the projection 22, so that the bolt ID will be retained in retracted position. On the door being reclosed, the ball M will be pushed back by the door frame so that the bell crank 40, M will be disengaged -from theprojection 22, and the lock bolt ID will again be shot by the spring I l, the other elements being also restored to the position shown in Fig. 1. Should it be desired to retain the lock bolt in retracted position while the door is closed, the bolt is is, after the door has been opened, pushed by hand a little further into the lock, so that the tooth 38 of the catch 37 will engage in the notch and secure the bolt in the position shown in Fig. 3. In this movement of the catch, its lower arm 39 strikes against the pin H and prevents the clockwise movement which the catch would otherwise perform under the influence of its own spring as well as of the spring H acting through the medium of the bolt 10. In order to release the bolt from the catch 31, the catch must be turned anti-clockwise by means of the key i5 until the tooth 33 slips out of the notch 35, whereupon the bolt !9 will be shot by the spring I I. If the door is closed the bolt will move into the position shown in Fig. 1; if the door is opened the bolt will move as far as the bell crank 40, 4| will a low.

The opening of the door from the inside can be effected by means of a handle after the bolt ID has been moved, by co-operation between the key l6 and the abutment 2| into the position shown in Fig. 2.

In the closed position of the door (Fig. l), the tooth 39 of the catch 31 is located in the neighbourhood of the notch 35, and the arm 38' is close to the pin II. By giving the key IS a quarter of a turn to the right, the catch 31 will be turned so that the tooth 39 leaves the notch 35 and so that the arm 38' strikes against the pin l i. At the same time the catch 31 will be locked in this position by the key l6 so as to prevent the door from being opened from. the outside.

On an attempt to open the door with a false key, one of the tumblers is likely to be turned too far, so that the lever 55, 56 will take up the position shown by dotted lines in Fig. 5. The signalling circuit will then be closed, and the signal will be operated until the lever 55, 56 is restored to normal position by the insertion of the rod 68.

An attempt to open the lock by force, for instance by the. insertion of a tool intended to force the bolt ill into the lock casing, the projection 22 will almost immediately enter into engagement with the spring 26 which, on continued inward movement or" the bolt, imparts to the respective tumbler a movement which will eventually cause the closing of the signalling circuit through the lever 55, 56, and the signal will then remain in operation as previously described.

The invention is not restricted to the actual lock construction illustrated in the drawings but may be modified within the limits imposed by the appended claim. For instance, the blade spring 25 can be replaced by a rigid rod or the like connected to the head of the respective tumbler and adapted to engage with its free. end in the recess 24.

I claim:

A door lock of the character described comprising a lock casing, a lock bolt in said casing, a projection on said lock bolt, key operated tumblers mounted. pivotally in the casing on an axis at right angles to but out of alignment with the path of said projection and located in a vertical plane horizontally distanced from that of the projection, each tumbler having an arm whereby it is normally supported on the bolt, said arm being in substantial alignment with the path of the projection and operative, except when the tumbler is operated by the proper key, to engage said projection for preventing the bolt from being retracted, the arm of one of the tumblers being flexible and longer than the others and operative to pivot its tumbler under inward pressure thereon by the bolt, and a circuit closing element so arranged in relation to the tumblers as to be operated thereby for closing an electric circuit when the tumbler having the flexible arm is moved by said arm or when the same and the other tumblers are moved through more than the normal angle.

CARL MAR'ITEN BIDEFELDT. 

